package com.lagou.edu.utils;

import lombok.extern.slf4j.Slf4j;
import org.springframework.http.HttpHeaders;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.util.StringUtils;

/**
 * @Classname IpUtils
 * @Date 2021/5/30 23:33
 * @Author ch'ien
 */
@Slf4j
public class IpUtils {

    /**
     * 获取IP地址
     * 使用Nginx等反向代理软件， 则不能通过request.getRemoteAddr()获取IP地址
     * 如果使用了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP地址，X-Forwarded-For中第一个非unknown的有效IP字符串，则为真实IP地址
     */
    public static String getIpAddr(ServerHttpRequest request) {

        HttpHeaders headers = request.getHeaders();
        String ip = headers.getFirst("X-Forwarded-For");
        try {

            if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
                ip = headers.getFirst("Proxy-Client-IP");
            }
            if (StringUtils.isEmpty(ip) || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = headers.getFirst("WL-Proxy-Client-IP");
            }
            if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
                ip = headers.getFirst("HTTP_CLIENT_IP");
            }
            if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
                ip = headers.getFirst("HTTP_X_FORWARDED_FOR");
            }
            if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getRemoteAddress().getAddress().getHostAddress();
            }
        } catch (Exception e) {
            log.error("IPUtils ERROR ", e);
        }
        // 使用代理，则获取第一个IP地址
        if (!StringUtils.isEmpty(ip) && ip.length() > 0) {
            ip = ip.split(",")[0];
        }
        return ip;
    }

}
